[Mechanism of molecular backgrounds of osteoarthritis].

In efforts to know the molecular backgrounds underlying the osteoarthritis (OA) development, examinations using the experimental mouse models confirmed that type X collagen (COL10A1) that is characteristic of chondrocyte hypertrophy and initiates endochondral ossification was strongly expressed in the OA cartilage. Recent COL10A1 gene transcription assay and mouse genetic approaches found that endochondral ossification signals like hypoxia-inducible factor 2α (HIF-2α), Runx2, C/EBPβ, carminerin, syndecan-4, hedgehog, and Notch signaling are involved in the OA development. The endochondral ossification process is likely to cause osteophyte formation at the periphery cartilage of the joint and degradation at the center during OA progression. Molecules related to endochondral ossification might become therapeutic targets altering the course of this disabling disease.